| With the fast development of wireless communications technology, spectrum resource has become more and more scarce. Spectrum resource is non-renewable. In order to make the best of the spectrum resource, Cognitive Radio technology emerges, and has been extensive research and development already. Spectrum sensing technology has become the basis and premise of Cognitive Radio technology. Now the research on spectrum sensing technology was mainly focused on the field of single node spectrum detection and multi-node spectrum detection. The service condition of the spectrum can be judged accurately by dealing with the detection information of cognitive users for the cooperative detection. In order to improve the spectrum detection performance, the cooperative spectrum detection and the uncertainty of the spectrum detection are studied further based on analyzing the existing research results. The main work of this paper is as follows.Firstly, to overcome the impact on the spectrum detection performance due to the same threshold value, a multi-users'cooperative spectrum detection algorithm based on energy detection is proposed by using the idea of grouping. The cooperative spectrum detection based on two users is extended that based on multi-users in the algorithm.Secondly, the uncertainty during the process of the spectrum detection is caused by the random of the channel in the Cognitive Radio network. To minimize the impact on the spectrum detection because of the uncertainty, the evidence conflict is considered. Then the D-S evidence theory is improved and the improved algorithm is applied in the cognitive radio detection technology, which makes that the D-S evidence theory is applied better.Finally, the cooperative spectrum detection is compared with the single node spectrum detection by simulation experiment. And the proposed cooperative spectrum detection based on the energy detection is verified. As a result, the optimal combination way based on the multi-users is summed up. |
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